Indicating light and test circuit



H. J- TYLER INDICATING LIGHT AND TEST CIRCUIT Filed Dec. 7, 1953 Toindicator Circuir INVENTOR Hu' h J'.T ler. BY 9 V WITNESSES:

ATTORNEY United States Patent 6 INDICATING LIGHT AND TEST CIRCUIT HughJ. Tyler, Pittsburgh, Pa., assignor to Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of PennsylvaniaApplicationDecember 7, 1953, Serial No. 396,668 2 Claims. (Cl; 340-214My invention relates, generally, to indicating lights, and, moreparticularly, to indicating lights of the type utilized on switchboardsand control panels.

Indicating lights are provided on switchboards and control panels toindicate the condition and/or operating position of apparatus locatedremotely from a switchboard or control panel. Heretofore,;in someinstances the reliability of the indicating lights has beenincreased byconnecting two lamps in parallel in the indicating circuit. Theprobability that both lampsfwould be burned out at the same time is verylow. Also, the lamps were transfererd to a test circuit by a separatepushbutton or other switching means in order to test a lamp while it isin service. Both of the previous methods have certain disadvantages,such as, the requirement of additional apparatus and mounting space forthe additional apparatus. Additional labor is also required to mount andconnect the additional apparatus, thereby further increasing the cost ofthe equipment.

An object of my invention is to simplify the structure and improve theoperation of an indicating light and associated circuit.

Another object of my invention is to provide an indicating lightstructure having a test circuit for the indicating lamp incorporatedwith the structure.

Other objects of my invention'will be explained fully hereinafter orwill be apparent to those skilled in the art.

In accordance with one embodiment of my invention, an indicating lampand push button are so combined in a single unit that the lamp may betransferred from the indicating circuit to a test circuit by merelypushing on the lens for the lamp. A source of potential is directlyconnected to test contact members so mounted in the unit structure thatthey are engaged by the lamp contact members when the lens is depressed,thereby determining if the lamp is burned out.

For a better understanding of the nature and objects of the invention,reference may be had to the following detailed description, taken inconjunction with the accompanying drawing, in which the single figure isa view in section of an indicating light unit embodying the principalfeatures of the invention.

Referring to the drawing, the structure shown therein comprises aportion of a switchboard or control panel 10 upon which is mounted anindicating light unit 11. The unit 11 comprises a sleeve 12 which isdisposed in an opening 13 in the panel 10. The sleeve 12 may be composedof any suitable insulating material.

As shown, one end of the sleeve has an external flange 14 thereon whichengages one side of the panel 10. The sleeve 12 also has an internalflange 15 thereon, the function of which will be more fully explainedhereinafter. A nut 16 is threaded on a portion of the sleeve 12 andengages the side of the panel 10 opposite the flange 14, therebyretaining the sleeve in position on the panel.

A base 17, which is composed of a suitable insulating material, isslidably but non-rotatably disposed in the sleeve 12. The base 17 isbiased outwardly by a spring 18 which is disposed between a snap ring 19and a shoulder 21 on the base 17. In the structure shown, the outwardmovement of the base 17 is limited by the internal flange 15 on thesleeve 12 and also by the snap ring 19 which engages a shoulder 22 onthe base 17. Thus, the possibility of the force of the spring 18breaking the flange 15 is precluded.

The base 17 has a central well or opening 23 therein in which a lampbulb 24 is mounted. The bulb illus-- trated is of the bayonet base typeand is provided with prongs 25 which engage a metal socket 26 disposedin the opening 23. It will be understood that a bulb having a screw basemay be utilized if desired.

One terminal of the lamp bulb 24 is electrically connected to a contactmember 27 which is carried by and moved with the base 17. The connectionto the contact member 27 extends from the bulb 24 through a contactbutton 28, which is mounted in an insulating disc 29, and a conductor 31which is connected to the member 27. The disc 29 is biased outwardlyagainst the socket 26 by a spring 32. The other terminal of the bulb 24is electrically connected to a contact member 33 which is carried by andmoved with the base 17. The connection to the member 33 extends throughthe socket 26 and a conductor 34.

When'the base 17 is biased outwardly to the position shown in thedrawing the contact members 27 and 33 engage fixed contact members 35and 36, respectively.

. As shown, the contact members 35 and 36 are L-shaped and extendthrough the sleeve 12. Terminal screws 40 are provided at the lower endsof the contact members 35 and 36 for making electrical connectionsthereto.

As shown, the contact members 35 and 36 may be connected to an indicatorcircuit, thereby connecting the lamp 24 to the indicator circuit whenthe base 17 is biased outwardly to its normal operating position. Thus,the bulb 24 functions to indicate the condition or operating position ofapparatus located remotely from the switch board panel 10 and connectedto the bulb through the indicator circuit.

A lens 37, which may be composed of translucent material, covers thebulb 24. The lens 37 may be of a particular color, thereby indicating aparticular condition or position of the apparatus associated with theindicator circuit. As shown, the lens 37 is threaded into the base 17,thereby permitting it to be removed in order to replace the lamp bulb24. The base 17 may be prevented from rotating by a screw 43 whichextends through the sleeve 12 into a groove 44 in the base 17.

In order to test the lamp bulb 24 the lens 37 may be depressed, therebymoving the base 17 inwardly against the pressure of the spring 18. Whenthe base 17 is moved inwardly the contact members 27 and 33 engagecontact members 38 and 39, respectively. The contact members 38 and 39may be connected directly to a reliable source of electromotive force,such as a battery 41. Thus, if the lamp is in operating condition itwill light when the base 17 is depressed since its terminals areconnected across the battery 41. The failure of the lamp to light whenthe base 17 is depressed indicates that it is burned out and should bereplaced.

The contact members 38 and 39 are mounted in an insulating member 42which may be attached to the bottom of the sleeve 12 by screws (notshown). Thus, the unit 11 constitutes a combined indicating and testingdevice. During normal operation the lamp 24 functions as an indicatinglight which is connected to an indicator circuit. The lens 37 isilluminated to give an indication of the condition of the apparatusassociated with the indicator circuit.

When it is desired to test the lamp 24 it is only neclamp 24 to the testcircuit. Therefore; it isnot'necessary to supplyarasseparate push buttonandassociated'cir- Q its. v or testing the indicating. light:Furthermore, it is. not necessary to supply an extra lamp which isconnected in parallel-circuit relation with the lamp 24 in order o in ese he e1i ility;- of: the 'indicatingq ght? it. ne-c he lamni em eberedi y s edtede ermin aitis-in per g-condi o ro he or ei e. d script o t's ppa nt havl: h vProvided a si pl and mpa t' n t hich fumei ns as n ndc g li htnd a st ng: v for the indicating light. The unit may be readily'manufactured and s m led au t is ui able f r o tin on a it hboar r enra P n How er; t may e: mou d on her eq pment:ii:desired Since tnumerusr ha ges mayv be ma e i -the: above-- s rib d: c ru caz nd dit e nt'mb diments he invention y be m e itho tfleper nefrom espir tand s e heeo is i ended-t at m e containediin he o e' o ng s p io or ho nn; hecpanying; drawingshall be interpreted as illustrative and notinsalimitingsense.

I claim as-my invention:

1. In an indicating light, in'combination, a sleeve; an insulating-baseslidably disposed insthe sleeve, a spring; biasing said I baseoutwardly,- stop"mea nslimiting the. outward movement of the base, a:larnpflqnlbv removably mounted in .the base, a -lens:di sposed over'thebulb andextending beyond the endofithe sleeve, a pair-ofspaced: movablecontact members carried by the base; apairgpf: pa ed. C n a t m m s fiedinhe sl eveandinormal y ng ed y d. mo able contac s ndq n dd ti natzPairct pacedvfix d. ntact membe sidispc edzte beet. sese y e. m v b evntac hec t a sl l ns isade pr sed, said mov tac sh eidispos dbetw en--said pairs offixedicontacts and electrically connected to said' 'lampbulb.

indicatingel ght, ia combination, a sl e e, an insulating base movablydisposed in the sleeve, a spring disposed in the sleeve andtbiasing saidbase outwardly, stop means limiting the outward movement of the base, alamp bulb mounted in the base, a lens covering the bulb and movable withthe base, a pair of spaced movable contact members carried 'b'ythe baseand electrically conuectecl to' the lampr' bulb', a pair' of; spacedcontact 'members fixed in the sleeve and normally engaged by Referenes-site he'fil f his'pat n UNITEDL-STATES PATENTS p Marco: July 29,,"v1947 2424,574 1947' 2510;37 .1952" 26253863." v 1.9.53.

GreatBritain* Mar. 25, 1949'

